Analyte Certified Concentration Analyte Certified Concentration(pg/g) (pg/g)2,3,7,8-TCDD. 262 ± 51 1,2,3,7,8-PeCDF . 46 ± 10total TCDD . 418 ± 1252,3,4,7,8-PeCDF . 88 ± 281,2,3,7,8-PeCDD. 28 ± 14 total PeCDF. 916 ± 351total PeCDD . 253 ± 150 1,2,3,4,7,8-H